At the end of the discussion, the teacher became angry and left the building, according to administrators.

School officials hired a private investigator to follow him because they were concerned.

He was followed to a Bass Pro Shops location where he allegedly purchased a gun and ammo. Police were notified after the purchase and followed the teacher as he headed back toward Sandy Springs and the school was placed on lockdown due to a "possible external threat".

Police said they soon pulled him over in a traffic stop adding that he was loading the gun when they found him. During that traffic stop, he was taken into custody.